THE NEBULAR HYPOTHESIS 235 



into a mathematical criticism of the opinion of Plato 

 " that the motion of the planets is such as if they had 

 all been created by God in some region very remote 

 from our system, and let fall from thence towards the 

 sun, their falling motion being turned aside into a 

 transverse one whenever they arrived at their several 

 orbits." This, of course, is wholly unlike Herschel's 

 theory, or that of Laplace. But of these letters Sir 

 David says: "In the present day they possess a 

 peculiar interest. They show that the Nebular 

 Hypothesis, the dull and dangerous heresy of the age, 

 is incompatible with the established laws of the 

 material universe, and that an omnipotent arm was 

 required to give the planets their position and 

 motions in space, and a presiding intelligence to 

 assign to them the different functions they had to 

 perform." 



These views of Sir David Brewster, eminent man of 

 science though he was and sincere believer in an 

 almighty arm ruling all the motions of material bodies, 

 do not seem justified by facts. Even his great name 

 is not weighty enough to counterbalance that of 

 Laplace, when the former affirms and the latter denies 

 that the Nebular Hypothesis " is incompatible with the 

 established laws of the material universe." Newton's 

 speculations on Plato's dream of the origin of planets 

 had nothing to do with the hypothesis in question. It 

 may be " a dull and dangerous heresy," as Sir David 

 believed, " but it denies neither an almighty arm nor a 

 presiding mind." Recent discoveries have given more 

 probability to the theory if we are entitled to use that 

 name: and Herschel's inductions from observed and 

 classified facts have gone far to prove that Laplace's 



